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Biomedical subjects

R F Breiman

Publications and source records attributed to R F Breiman.

At least 73 records · Page 4Linked to original sources

Multiple antimicrobial resistance of pneumococci in children with otitis media, bacteremia, and meningitis in Slovakia.

Penicillin-resistant pneumococci have been isolated from middle ear fluid, blood, cerebrospinal fluid, and nasopharyngeal secretions of several hundred children in Slovakia since 1985; 116 of these isolates were serotyped and tested for susceptibility to antimicrobial drugs at the Centers for Disease Control and Prevention. To define the prevalence of drug-resistant pneumococci and identify risk factors for infection, laboratory and medical records were reviewed. Nearly all (96%) of the resistant strains tested were serotype 14. Of these, all were resistant to penicillin (MIC, 4-16 micrograms/mL); most were resistant to cefaclor, erythromycin, tetracycline, and chloramphenicol; and many had decreased susceptibility to trimethoprim-sulfamethoxazole and ceftriaxone. Frequent antibiotic use, prior hospitalization, and length of hospital stay (P < .001 for all 3) were associated with infection with resistant strains. These findings suggest the need for routine screening of pneumococcal isolates for penicillin resistance and highlight the importance of controlling globally the spread of resistant pneumococci.

Bacteremia↗

Evaluation of the magnitude of the 1993 hantavirus outbreak in the southwestern United States.

In May 1993, an outbreak of hantavirus pulmonary syndrome (HPS) in the southwestern United States was caused by the previously unrecognized Sin Nombre virus (SNV). Most HPS patients had an influenza-like prodrome, followed by rapid onset of pulmonary edema (fatality rate, 52%). To define the magnitude of the outbreak, patients with milder illnesses who sought medical care in the outbreak area during the outbreak period were assessed for infection with SNV. Of 299 study subjects, 43 had illnesses similar to the HPS prodrome. One laboratory finding, thrombocytopenia, was highly discriminatory between non-HPS patients (1%) and confirmed HPS patients (71%; P < .001) during the prodrome phase. No study subject had serologic evidence (IgM antibodies) of recent SNV infection. Five had IgG titers consistent with a previous hantavirus infection: 3 of these 5 were among the 43 patients who had illnesses similar to the HPS prodrome (P < .05). These data provide evidence that mild illness is rarely caused by SNV.

Adolescent↗

Risk factors for invasive disease caused by Streptococcus pneumoniae among Alaska native children younger than two years of age.

Streptococcus pneumoniae causes a significant amount of illness and death from pneumonia, bacteremia and meningitis among children < 2 years of age. No currently available effective vaccine exists to prevent pneumococcal disease in this age group. To identify modifiable risk factors we conducted a retrospective case-control study of 29 Alaska Native residents of Bethel, AK, < 2 years of age who had invasive pneumococcal illness from 1983 to 1992 and 85 controls matched for race, city of residence and date of birth. Data were collected through reviews of medical records and telephone interviews. In matched univariate analysis the following variables were associated with illness at P < or = 0.25 and were included in the multivariate model: at least one prior episode of pneumonia; at least one prior hospitalization; group child care center attendance; at least one tobacco smoker in the household; at least one tobacco chewer in the household; and lack of breast-feeding. Using a conditional multiple logistic regression analysis, we found that group child care center attendance (odds ratio, 98.6; 95% confidence interval, 5.1 to 1920.6) and the presence in the household of at least one person who chewed tobacco (odds ratio, 20.6; 95% confidence interval, 1.4 to 294.5) were independently associated with illness while breast-feeding was protective (odds ratio, 0.1; 95% confidence interval, 0.0 to 1.0). These data suggest that breast-feeding may prevent invasive pneumococcal disease and that strategies for decreasing risks should target children in group child care settings. Further studies are needed to evaluate the interaction of tobacco and pneumococcal illness.

Alaska↗

High prevalence of multidrug-resistant Streptococcus pneumoniae among children in a rural Kentucky community.

In 1992 drug-resistant Streptococcus pneumoniae was cultured with increasing frequency from aspirates of middle ear fluid from children with acute otitis media in a rural Kentucky community. To determine the prevalence of carriage of drug-resistant S. pneumoniae in the community, we obtained nasopharyngeal swabs from 158 (70%) of 227 children attending a child daycare center and from 82 children attending the county health center. S. pneumoniae was isolated from 126 children. Among 123 isolates tested 65 (53%) were penicillin-resistant, including 41 (33%) strains that were highly resistant; 61 (50%) were multidrug-resistant. Serotypes 19F, 6B, 23F and 6A comprised 89% of the penicillin-resistant isolates. Detection of a variety of serotypes and drug resistance patterns among nasopharyngeal isolates of S. pneumoniae suggests that multidrug-resistant pneumococcal strains are endemic in this community. Surveillance for drug-resistant pneumococci with the use of respiratory secretions obtained by nasopharyngeal swab may provide useful information on the prevalence of drug-resistant strains causing invasive disease and otitis media. Such information could be used to guide empiric therapy of pneumococcal infections.

Carrier State↗

Comparison of Legionella pneumophila isolates by arbitrarily primed PCR and pulsed-field gel electrophoresis: analysis from seven epidemic investigations.

Arbitrarily primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE) subtyping were applied to clinical and environmental isolates from seven unrelated outbreaks of Legionnaires' disease. The patterns observed with each method matched patient isolates and the epidemiologically linked source of disease for each of the seven outbreaks. PFGE allowed more discrimination among various isolates, although AP-PCR usually gave comparable results. With both methods, certain patterns appeared to predominate in the comparison of the seven outbreaks. Of five clinical isolates not associated with the outbreaks, three gave profiles distinct from those observed in the outbreaks by both methods. This suggests that there are at least two predominant subtypes of Legionella pneumophila serogroup 1 associated with outbreaks. Investigations of outbreaks of legionellosis should employ either PFGE or AP-PCR in addition to monoclonal antibody analysis.

Bacterial Typing Techniques↗

Surveillance for Legionnaires' disease. Risk factors for morbidity and mortality.

BACKGROUND: To augment available information about the epidemiology of legionnaires' disease, we analyzed data reported to the passive surveillance system at the Centers for Disease Control and Prevention, Atlanta, Ga, from 1980 through 1989. METHODS: Risk of disease associated with specific demographic characteristics and health conditions was calculated by comparing the surveillance group with the US population. Risk of death was calculated using multivariate logistic regression models. RESULTS: A diagnosis of legionnaires' disease was confirmed on the basis of clinical and laboratory criteria for 3254 patients. Disease rates did not vary by year, but were higher in the northern states and during the summer. Legionella pneumophila, serogroup 1, constituted 71.5% of fully identified isolates. This study confirmed previously identified risk factors for legionnaires' disease. In addition, a markedly elevated risk was identified for persons with acquired immunodeficiency syndrome (rate ratio, 41.9; 95% confidence interval, 12.9, 71.0), or hematologic malignancy (rate ratio, 22.4; 95% confidence interval, 19.0, 25.9). Likelihood of death was increased in patients who were elderly or male; those with hospital-acquired infection, renal disease, malignancy, or immunosuppression; and those from whom L pneumophila, serogroup 6, was isolated. CONCLUSIONS: Infection with Legionella remains an important cause of disease and death in the United States. Diagnosis and treatment of legionnaires' disease should be targeted at patients at increased risk for illness and complications due to Legionella infection. Diagnostic tests for legionnaires' disease based on species other than L pneumophila, serogroup 1, should be developed and tested. Recommendations for prevention of legionnaires' disease should be focused on settings where there are persons at greatest risk for illness or serious outcome.

Adolescent↗

An epidemic of pneumococcal disease in an overcrowded, inadequately ventilated jail.

BACKGROUND: In the United States many correctional facilities now operate at far over capacity, with the potential for living conditions that permit outbreaks of respiratory infections. We investigated an outbreak that was identified in an overcrowded Houston jail after two inmates died of pneumococcal sepsis on the same day. Outbreaks of pneumococcal disease have been rare in the era of antibiotics. METHODS: We assessed risk factors for pneumococcal disease in both a case-control and a cohort study. Ventilation was evaluated by measuring carbon dioxide levels and air flow to the living areas of the jail. The extent of asymptomatic infection was determined by culturing pharyngeal specimens from a random sample of inmates. Type-specific immunity was determined with an enzyme immunoassay. RESULTS: Over a four-week period, 46 inmates had either acute pneumonia or invasive pneumococcal disease due to Streptococcus pneumoniae serotype 12F. The jail's capacity had been set at 3500 inmates, but it housed 6700 at the time of the outbreak; the inmates had a median living area of only 34 ft2 (3.2 m2) (interquartile range, 28 to 56 ft2 [2.6 to 5.2 m2]) per person. There were significantly fewer cases of disease among inmates with 80 ft2 (7.4 m2) per person or more (P = 0.030). Carbon dioxide levels ranged from 1100 to 2500 ppm (acceptable, < 1000), and the ventilation system delivered a median of only 6.1 ft3 of outside air per minute per person (interquartile range, 4.4 to 8.5 ft3; recommended, > or = 20 ft3). The attack rate was highest among inmates in cells with the highest carbon dioxide levels and the lowest volume of outside air delivered by the ventilation system (relative risk, 1.94; 95 percent confidence interval, 1.08 to 3.48). Of underlying medical conditions, intravenous drug use was most strongly associated with disease (odds ratio, 4.50). The epidemic strain (serotype 12F) was cultured from 7 percent of the asymptomatic inmates. Of 11 case patients tested with the enzyme immunoassay, 9 (82 percent) lacked preexisting immunity to this strain. CONCLUSIONS: Severe overcrowding, inadequate ventilation, and altered host susceptibility all contributed to this outbreak of pneumococcal disease in a large urban jail.

Adult↗

Emergence of drug-resistant pneumococcal infections in the United States.

OBJECTIVE: To estimate drug susceptibility patterns of Streptococcus pneumoniae in selected hospitals in the United States and to characterize the epidemiology of invasive drug-resistant pneumococcal infections. DESIGN: Minimum inhibitory concentrations (MICs) for a variety of commonly used antimicrobial drugs were determined for pneumococcal isolates submitted to the Centers for Disease Control and Prevention (CDC). Risk factors for drug-resistant pneumococcal infection were evaluated. SETTING: Hospital laboratories in the United States submitting pneumococcal isolates to the CDC between October 1, 1991, and September 30, 1992. PARTICIPANTS: A total of 544 persons with pneumococci isolated from normally sterile sites. RESULTS: A total of 13 hospitals in 12 states actively participated in an ongoing pneumococcal surveillance study. Resistance to penicillin was detected in 6.6% of isolates, including 1.3% of isolates with MICs of 2.0 micrograms/mL or more (compared with < 0.02% of isolates with MIC > or = 2.0 micrograms/mL identified by CDC surveillance from 1979 to 1987). A total of 16.4% were resistant to at least one of the following drugs or drug classes: penicillin, cephalosporins, macrolides, combination trimethoprim and sulfamethoxazole, and chloramphenicol. Six serotypes (6B, 23F, 14, 9V, 19A, and 19F) accounted for nearly 85% of strains resistant to at least one drug class. Children were more likely than adults to be infected with strains resistant to trimethoprim-sulfamethoxazole, erythromycin, or chloramphenicol. CONCLUSIONS: Emergence of drug-resistant pneumococcal infections will present critical challenges to clinicians for treating patients with pneumococcal disease. Widened and intensified surveillance is needed. These data suggest that current recommendations for use of 23-valent pneumococcal capsular polysaccharide vaccines should be aggressively promoted and that development and evaluation of new conjugate pneumococcal vaccines may be a crucial part of strategies for prevention.

Anti-Bacterial Agents↗

Risk factors for transmission of Mycobacterium tuberculosis in a primary school outbreak: lack of racial difference in susceptibility to infection.

Recent data have suggested that there are racial differences in the susceptibility to infection by Mycobacterium tuberculosis. An opportunity to test this suggestion was afforded by an outbreak of tuberculosis in a racially mixed elementary school in St. Louis County, Missouri. A physical education teacher was discovered to have cavitary pulmonary tuberculosis. Of 343 students in the school, 176 (51 percent) were found to be tuberculin skin test positive (> or = 5 mm induration by Mantoux method); 32 children had abnormal chest radiographs. More frequent contact with the physical education teacher was associated with infection (p < 0.001). Black children were no more likely to be infected than were white children (relative risk (RR) = 0.98, 95% confidence interval (CI) 0.78-1.22). However, black children who were tuberculin positive had larger skin reactions than did white children (mean, 18.9 vs. 16.6 mm, p < 0.001) and were more likely to have abnormal chest radiographs (RR = 2.76, 95% CI 1.44-5.27). Among tuberculin-positive children, low body mass index (less than 10th percentile) was associated with active disease (RR = 2.90, 95% CI 1.45-5.80). The analysis of race was unchanged after controlling for sex, body build, and level of contact with the physical education teacher. Widespread tuberculous infection resulted from contact with a highly infectious staff person. Thin body build was a risk factor for active disease. Black children were no more susceptible to infection than were white children, although they more commonly developed radiographic evidence of active disease.

Adult↗

Radiographic appearance of Chlamydia pneumoniae (TWAR strain) respiratory infections. CBPIS Study Group. Community-based Pneumonia Incidence Study.

PURPOSE: To report the spectrum of radiographic findings associated with a new respiratory pathogen: Chlamydia pneumoniae (TWAR strain). MATERIALS AND METHODS: Radiographs of 55 adult patients hospitalized with serologic evidence of C pneumoniae were retrospectively reviewed. RESULTS: On the basis of serologic criteria, two types of acute respiratory infection are possible: primary (first exposure) infections and recurrent, acute infection in a previously exposed individual. In the primary group, alveolar opacities (65%) with a unilateral distribution (71%) were most common at admission. Cavitary disease and hilar or mediastinal lymphadenopathy were uncommon. Small to medium-sized pleural effusions were common in both primary and recurrent groups during hospitalization. Also, both groups tended to progress to bilateral, mixed, interstitial and alveolar changes during the course of infection. CONCLUSION: Different radiographic patterns exist for the two types of acute C pneumoniae infection.

Acute Disease↗

Pneumococcal polysaccharide vaccine efficacy. An evaluation of current recommendations.

OBJECTIVE: To determine pneumococcal polysaccharide vaccine efficacy in selected populations at risk for serious pneumococcal infection for whom vaccination is currently recommended and to assess duration of protection after vaccination. DESIGN: Vaccine efficacy was estimated using indirect cohort analysis to compare the proportion of pneumococcal infections caused by serotypes included in the vaccines of vaccinated and unvaccinated persons who were identified during 14 years of national surveillance. SETTING: Hospital laboratories in the United States that submitted pneumococcal isolates to the Centers for Disease Control and Prevention between May 1978 and April 1992. PARTICIPANTS: A total of 2837 persons older than 5 years who had pneumococcus isolated from blood or cerebrospinal fluid. RESULTS: Overall efficacy for preventing infection caused by serotypes included in the vaccine was 57% (95% confidence interval [CI], 45% to 66%). Efficacy among persons with diabetes mellitus was 84% (95% CI, 50% to 95%); with coronary vascular disease, 73% (95% CI, 23% to 90%); with congestive heart failure, 69% (95% CI, 17% to 88%); with chronic pulmonary diseases, 65% (95% CI, 26% to 83%); and with anatomic asplenia, 77% (95% CI, 14% to 95%). Efficacy was not documented for patients with alcoholism or cirrhosis, sickle cell disease, chronic renal failure, lymphoma, leukemia, or multiple myeloma, although sample sizes were small for these groups. Efficacy for immunocompetent persons older than 65 years was 75% (95% CI, 57% to 85%). Efficacy did not decline with increasing interval after vaccination: 5 to 8 years after vaccination it was 71% (95% CI, 24% to 89%), and 9 years or more after vaccination it was 80% (95% CI, 16% to 95%). CONCLUSIONS: Intensified efforts to improve pneumococcal vaccine coverage among certain populations for whom vaccination is currently recommended is indicated, but universal revaccination is not warranted at this time.

Adolescent↗

The changing epidemiology of invasive group A streptococcal infections and the emergence of streptococcal toxic shock-like syndrome. A retrospective population-based study.

OBJECTIVE: To determine disease incidence and changes in the epidemiology of invasive group A streptococcal infections in a community in Arizona. DESIGN AND SETTING: We retrospectively surveyed microbiology records from all 10 hospitals in Pima County, Arizona, to identify patients who had Streptococcus pyogenes isolated from blood, sterile body fluid, or tissue biopsy specimens between April 1985 and March 1990. Demographic and clinical information was abstracted from the medical records of these patients. PATIENTS: A total of 128 patients with a median age of 53.5 years (range, 6 months to 96 years). OUTCOME MEASURES: Racial/ethnic differences in disease incidence; mortality and changes in the clinical spectrum of disease over the study period. RESULTS: The annual age-adjusted incidence was 4.3 per 100,000 but was 46.0 per 100,000 among Native Americans. Advanced age, age less than 5 years, hypotension, and multi-organ system involvement were significantly associated with increased mortality. From 1985 to 1990, the proportion of infections with hypotension, rash, desquamation, renal impairment, and gastrointestinal involvement increased significantly (chi 2 for trend P < or = .02 for each feature). A toxic shock-like syndrome occurred in 8% of infections since 1988, compared with none of the infections between 1985 and 1987 (P = .04). Patients with the syndrome were younger than patients with other invasive infections (median age 15 vs 54 years, P = .02), and were less likely to have underlying medical conditions (P = .008). CONCLUSIONS: Significant changes occurred in the spectrum of invasive group A streptococcal infections in Pima County, Arizona, between 1985 and 1990. Native Americans were at increased risk of acquiring these infections. Patients with the streptococcal toxic shock-like syndrome had epidemiologic features that distinguished them from patients with other invasive infections, including younger age and less underlying illness.

Adolescent↗

Use of nasopharyngeal isolates of Streptococcus pneumoniae and Haemophilus influenzae from children in Pakistan for surveillance for antimicrobial resistance.

Antimicrobial resistance of Streptococcus pneumoniae and Haemophilus influenzae presents a challenge to clinical case management, particularly in programs for acute respiratory tract infection (ARI), including pneumonia, in developing countries. To determine whether nasopharyngeal isolates of S. pneumoniae and H. influenzae from a clinically defined group of children could be used to predict the prevalence of antimicrobial resistance of strains that cause disease, 601 urban children with ARI, 133 healthy urban children and 285 rural children were evaluated in Pakistan. Of the urban children with ARI, 216 (35.9%) were bacteremic, predominantly with S. pneumoniae (108 children) and H. influenzae (100 children). Overall 631 (61.9%) children carried S. pneumoniae and 381 (37.4%) carried H. influenzae. The proportions of nasopharyngeal isolates of both organisms from urban children with ARI resistant to penicillin or ampicillin, trimethoprim/sulfamethoxazole, chloramphenicol and erythromycin were similar to the proportions of resistant blood isolates. Nasopharyngeal isolates from rural children had lower rates of resistance to some antimicrobial agents. These findings suggest that nasopharyngeal isolates of S. pneumoniae and H. influenzae from children with ARI can be used to conduct surveillance for antimicrobial resistance in a defined geographic area. Such surveillance would aid programs in developing countries in making a rational choice of antimicrobial agents for use in clinical management of bacterial diseases, including pneumonia.

Acute Disease↗

Association of phenotypic and genotypic characteristics of invasive Streptococcus pyogenes isolates with clinical components of streptococcal toxic shock syndrome.

Sixty-two invasive Streptococcus pyogenes strains, including 32 strains isolated from patients with streptococcal toxic shock syndrome (STSS), were analyzed for the following phenotypic and genotypic characteristics: M-protein type, serum opacity factor production, protease production, the presence of streptococcal pyrogenic exotoxin (Spe) genes A, B, and C, and in vitro production of SpeA and SpeB. These characteristics were analyzed for possible associations with each other as well as with clinical components of STSS. M-type 1, the most commonly isolated M-type, was significantly associated with protease production. Protease activity was significantly associated with the clinical sign of soft tissue necrosis. M-type 1 and 3 strains from STSS patients were significantly associated with the clinical signs of shock and organ involvement as well as with SpeA production in vitro. Finally, the production of SpeA was significantly associated with the clinical component of shock and organ involvement as well as with rash. These data suggest that STSS does not make up a single syndrome but, rather, that the multiple STSS clinical criteria probably reflect different phenotypic characteristics of individual S. pyogenes isolates.

Adolescent↗

Use of multiple molecular subtyping techniques to investigate a Legionnaires' disease outbreak due to identical strains at two tourist lodges.

A multistate outbreak of Legionnaires' disease occurred among nine tour groups of senior citizens returning from stays at one of two lodges in a Vermont resort in October 1987. Interviews and serologic studies of 383 (85%) of the tour members revealed 17 individuals (attack rate, 4.4%) with radiologically documented pneumonia and laboratory evidence of legionellosis. A survey of tour groups staying at four nearby lodges and of Vermont-area medical facilities revealed no additional cases. Environmental investigation of common tour stops revealed no likely aerosol source of Legionella infection outside the lodges. Legionella pneumophila serogroup 1 was isolated from water sources at both implicated lodges, and the monoclonal antibody subtype matched those of the isolates from six patients from whom clinical isolates were obtained. The cultures reacted with monoclonal antibodies MAB1, MAB2, 33G2, and 144C2 to yield a 1,2,5,7 or a Benidorm 030E pattern. The strains were also identical by alloenzyme electrophoresis and DNA ribotyping techniques. The epidemiologic and laboratory data suggest that concurrent outbreaks occurred following exposures to the same L. pneumophila serogroup 1 strain at two separate lodges. Multiple molecular subtyping techniques can provide essential information for epidemiologic investigations of Legionnaires' disease.

Adult↗